<title>教室安排</title><link href="http://hzoi.com/tomorrow.css" rel="stylesheet"><div class="ui existing segment"><pre><code><span class="pl-cp">#include</span> <span class="pl-cpf">&lt;algorithm&gt;</span><span class="pl-cp"></span>
<span class="pl-cp">#include</span> <span class="pl-cpf">&lt;cstdio&gt;</span><span class="pl-cp"></span>
<span class="pl-kt">long</span> <span class="pl-kt">long</span> <span class="pl-n">a</span><span class="pl-p">[</span><span class="pl-mi">101000</span><span class="pl-p">];</span>
<span class="pl-kt">int</span> <span class="pl-n">n</span><span class="pl-p">,</span> <span class="pl-n">c</span><span class="pl-p">;</span>
<span class="pl-kt">int</span> <span class="pl-nf">chack</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">x</span><span class="pl-p">)</span> <span class="pl-p">{</span>
    <span class="pl-kt">int</span> <span class="pl-n">cas</span> <span class="pl-o">=</span> <span class="pl-mi">1</span><span class="pl-p">,</span> <span class="pl-n">ch</span> <span class="pl-o">=</span> <span class="pl-n">a</span><span class="pl-p">[</span><span class="pl-mi">0</span><span class="pl-p">];</span>
    <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span> <span class="pl-o">=</span> <span class="pl-mi">1</span><span class="pl-p">;</span> <span class="pl-n">i</span> <span class="pl-o">&lt;</span> <span class="pl-n">n</span><span class="pl-p">;</span> <span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">)</span> <span class="pl-p">{</span>
        <span class="pl-k">if</span> <span class="pl-p">(</span><span class="pl-n">a</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]</span> <span class="pl-o">-</span> <span class="pl-n">ch</span> <span class="pl-o">&gt;=</span> <span class="pl-n">x</span><span class="pl-p">)</span> <span class="pl-n">ch</span> <span class="pl-o">=</span> <span class="pl-n">a</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">],</span> <span class="pl-n">cas</span><span class="pl-o">++</span><span class="pl-p">;</span>
        <span class="pl-k">if</span> <span class="pl-p">(</span><span class="pl-n">cas</span> <span class="pl-o">&gt;=</span> <span class="pl-n">c</span><span class="pl-p">)</span> <span class="pl-k">return</span> <span class="pl-nb">true</span><span class="pl-p">;</span>
    <span class="pl-p">}</span>
    <span class="pl-k">return</span> <span class="pl-nb">false</span><span class="pl-p">;</span>
<span class="pl-p">}</span>
<span class="pl-kt">int</span> <span class="pl-nf">solve</span><span class="pl-p">()</span> <span class="pl-p">{</span>
    <span class="pl-kt">int</span> <span class="pl-n">l</span> <span class="pl-o">=</span> <span class="pl-mi">0</span><span class="pl-p">,</span> <span class="pl-n">r</span> <span class="pl-o">=</span> <span class="pl-n">a</span><span class="pl-p">[</span><span class="pl-n">n</span> <span class="pl-o">-</span> <span class="pl-mi">1</span><span class="pl-p">]</span> <span class="pl-o">-</span> <span class="pl-n">a</span><span class="pl-p">[</span><span class="pl-mi">0</span><span class="pl-p">],</span> <span class="pl-n">mid</span><span class="pl-p">;</span>
    <span class="pl-k">while</span><span class="pl-p">(</span><span class="pl-n">r</span><span class="pl-o">-</span><span class="pl-n">l</span><span class="pl-o">&gt;</span><span class="pl-mi">1</span><span class="pl-p">){</span>
        <span class="pl-n">mid</span> <span class="pl-o">=</span> <span class="pl-p">(</span><span class="pl-n">l</span> <span class="pl-o">+</span> <span class="pl-n">r</span><span class="pl-p">)</span> <span class="pl-o">/</span> <span class="pl-mi">2</span><span class="pl-p">;</span>
        <span class="pl-k">if</span> <span class="pl-p">(</span><span class="pl-n">chack</span><span class="pl-p">(</span><span class="pl-n">mid</span><span class="pl-p">))</span> <span class="pl-n">l</span> <span class="pl-o">=</span> <span class="pl-n">mid</span><span class="pl-p">;</span>
        <span class="pl-k">else</span> <span class="pl-n">r</span> <span class="pl-o">=</span> <span class="pl-n">mid</span><span class="pl-p">;</span>
    <span class="pl-p">}</span>
    <span class="pl-k">return</span> <span class="pl-n">l</span><span class="pl-p">;</span>
<span class="pl-p">}</span>
<span class="pl-kt">int</span> <span class="pl-nf">main</span><span class="pl-p">()</span> <span class="pl-p">{</span>
    <span class="pl-n">freopen</span><span class="pl-p">(</span><span class="pl-s">&quot;classroom.in&quot;</span><span class="pl-p">,</span><span class="pl-s">&quot;r&quot;</span><span class="pl-p">,</span><span class="pl-n">stdin</span><span class="pl-p">);</span>
    <span class="pl-n">freopen</span><span class="pl-p">(</span><span class="pl-s">&quot;classroom.out&quot;</span><span class="pl-p">,</span><span class="pl-s">&quot;w&quot;</span><span class="pl-p">,</span><span class="pl-n">stdout</span><span class="pl-p">);</span>
    <span class="pl-n">scanf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d%d&quot;</span><span class="pl-p">,</span> <span class="pl-o">&amp;</span><span class="pl-n">n</span><span class="pl-p">,</span> <span class="pl-o">&amp;</span><span class="pl-n">c</span><span class="pl-p">);</span>
    <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span> <span class="pl-o">=</span> <span class="pl-mi">0</span><span class="pl-p">;</span> <span class="pl-n">i</span> <span class="pl-o">&lt;</span> <span class="pl-n">n</span><span class="pl-p">;</span> <span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">)</span> <span class="pl-n">scanf</span><span class="pl-p">(</span><span class="pl-s">&quot;%lld&quot;</span><span class="pl-p">,</span> <span class="pl-o">&amp;</span><span class="pl-n">a</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]);</span>
    <span class="pl-n">std</span><span class="pl-o">::</span><span class="pl-n">sort</span><span class="pl-p">(</span><span class="pl-n">a</span><span class="pl-p">,</span> <span class="pl-n">a</span> <span class="pl-o">+</span> <span class="pl-n">n</span><span class="pl-p">),</span> <span class="pl-n">printf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d</span><span class="pl-se">\n</span><span class="pl-s">&quot;</span><span class="pl-p">,</span> <span class="pl-n">solve</span><span class="pl-p">());</span>
    <span class="pl-k">return</span> <span class="pl-mi">0</span><span class="pl-p">;</span>
<span class="pl-p">}</span>
</cpde></pre></div>